Optical time domain reflectometer and display method of optical time domain reflectometer

ABSTRACT

An optical time domain reflectometer includes: an OTDR measurement unit; an event detection unit that detects an event using the measurement result of the OTDR measurement unit; a display unit that displays a plurality of icons indicating events in an event display region A IV  and displays information of an event, which is located in a specific region A ATT  of the event display region A IV , in an information display region A INF ; an operation detection unit that detects a swipe operation in the event display region A IV ; and an event-of-interest changing unit that scrolls the events displayed in the event display region A IV  according to the swipe operation to change the display of the information display region A INF  to information corresponding to the event indicated by the icon located in the specific region A ATT .

TECHNICAL FIELD

The present invention relates to an optical time domain reflectometerand a display method of an optical time domain reflectometer.

BACKGROUND ART

An optical time domain reflectometer (OTDR) has been used for detectingfault such as break, bend in an optical fiber. The amount of opticalfibers being laid has rapidly increased with an increase in the capacityof mobile traffic. However, there are an increasing number of caseswhere operators inexperienced in handling of optical fiber cables areusing an OTDR. Therefore, for OTDR, analysis results being easilyunderstandable and an intuitive operation are required (for example,refer to Non-patent Document 1).

FIG. 11 shows an example of the screen configuration disclosed inNon-patent Document 1. The screen is configured to include iconsindicating events Iv18 to Iv24 that are failure points of the opticalfiber detected by the analysis, details of an event Iv21 that is anevent of interest (location where the operator wants to check the line),and a hard key (not shown) for changing an event of interest providedoutside a display unit 113. In addition, the classification of failuresis shown by the symbol in each icon, an event of interest is displayedin an enlarged manner or displayed so as to be surrounded by a frame,and failure point information (distance, loss, and failureclassification) or the like is displayed in an information displayregion A_(INF). In a case where there is a failure, the operator changesthe event of interest by operating the hard key in order to identify theloss and the distance of the failure point.

RELATED ART DOCUMENT Non-Patent Document

-   [Non-patent Document 1] Taichi Murakami, Tatsuyuki Maki, Taiki    Fukushima, Tomohide Yamazaki, “Development of MT9083 Access Master    Fiber Visualizer and Optical Connector End Surface Inspection    Function”, ANRITSU Technical, No. 89, March 2014

DISCLOSURE OF THE INVENTION Problem that the Invention is to Solve

In the configuration described above, however, in a case where thenumber of events is high, it is necessary to press the hard key by thenumber of events when changing the event of interest. For this reason,in a case where the number of events is high, the number of operationswhen operating the optical time domain reflectometer disclosed inNon-patent Document 1 is increased. As a result, it is not possible tocheck for failures efficiently.

Therefore, it is an object of the present invention to provide anoptical time domain reflectometer in which an event of interest can bechanged through an intuitive operation and failure points can be checkedefficiently even in a case where the number of events increases.

Means for Solving the Problem

An optical time domain reflectometer according to a first aspect of thepresent invention includes: a measurement unit that makes a light pulsebe incident on an optical fiber under test and receives return lightthat returns due to reflection or scattering of the light pulse in theoptical fiber under test; an event detection unit that detects eventswhere an intensity of the return light changes; a display unit thatdisplays a plurality of icons corresponding to the events in an eventdisplay region and that displays information of an event, which isindicated by an icon located in a specific region of the event displayregion, in an information display region; an operation detection unitthat detects an amount of swipe operation in the event display region;and an event-of-interest changing unit that scrolls icons displayed inthe event display region according to the amount of swipe operation,which has been detected by the operation detection unit, to change thedisplay of the information display region to information correspondingto the event indicated by the icon located in the specific region.

According to a second aspect of the present invention, in the opticaltime domain reflectometer according to the first aspect of the presentinvention, the operation detection unit may detect a tap operation onthe icon, and the event-of-interest changing unit may scroll iconsdisplayed in the event display region to move the icon, at which the tapoperation has been detected, to the specific region.

According to a third aspect of the present invention, in the opticaltime domain reflectometer according to the first aspect of the presentinvention, the display unit may display an occurrence point of eachevent in the entire optical fiber under test in an occurrence pointdisplay region, the operation detection unit may detect a tap operationon an occurrence point in the occurrence point display region, and theevent-of-interest changing unit may scroll icons displayed in the eventdisplay region to move the icon of the event of the occurrence point, atwhich the tap operation has been detected, to the specific region.

According to a fourth aspect of the present invention, in the opticaltime domain reflectometer according to the second aspect of the presentinvention, the display unit may display an occurrence point of eachevent in the entire optical fiber under test in an occurrence pointdisplay region, the operation detection unit may detect a tap operationon the occurrence point in the occurrence point display region, and theevent-of-interest changing unit may scroll icons displayed in the eventdisplay region to move the icon of the event of the occurrence point, atwhich the tap operation has been detected, to the specific region.

According to a fifth aspect of the present invention, in the opticaltime domain reflectometer according to the first aspect of the presentinvention, the operation detection unit may detect a tap operation ontwo icons indicating two different events, a calculation unit thatcalculates a loss and a distance between the two events where the tapoperation has been detected may be further provided, and the displayunit may highlight the icon where the tap operation has been detectedand display the distance and the loss calculated by the calculation unitin the information display region.

According to a sixth aspect of the present invention, in the opticaltime domain reflectometer according to the first aspect of the presentinvention, the display unit may display an occurrence point of eachevent in the entire optical fiber under test in an occurrence pointdisplay region, the operation detection unit may detect a tap operationon two different occurrence points in the occurrence point displayregion, a calculation unit that calculates a loss and a distance betweenthe two occurrence points where the tap operation has been detected maybe further provided, and the display unit may highlight the occurrencepoints where the tap operation has been detected and display thedistance and the loss calculated by the calculation unit in theinformation display region.

According to a seventh aspect of the present invention, in the opticaltime domain reflectometer according to the first aspect of the presentinvention, the display unit may display a plurality of iconscorresponding to the events in order of the events in the optical fiberunder test.

According to an eighth aspect of the present invention, in the opticaltime domain reflectometer according to the second aspect of the presentinvention, the display unit may display a plurality of iconscorresponding to the events in order of the events in the optical fiberunder test.

According to a ninth aspect of the present invention, in the opticaltime domain reflectometer according to the fifth aspect of the presentinvention, the display unit may display a plurality of iconscorresponding to the events in order of the events in the optical fiberunder test.

According to a tenth aspect of the present invention, in the opticaltime domain reflectometer according to the first aspect of the presentinvention, the display unit may display the icon of the event located inthe specific region as an icon larger than icons of events locatedoutside the specific region.

According to an eleventh aspect of the present invention, in the opticaltime domain reflectometer according to the second aspect of the presentinvention, the display unit may display the icon of the event located inthe specific region as an icon larger than icons of events locatedoutside the specific region.

A display method of an optical time domain reflectometer according to atwelfth aspect of the present invention includes: a measurement step ofmaking a light pulse be incident on an optical fiber under test andreceiving return light that returns due to reflection or scattering ofthe light pulse in the optical fiber under test; an event detection stepof detecting events where an intensity of the return light changes usinga measurement result in the measurement step; a display step ofdisplaying a plurality of icons corresponding to the events in an eventdisplay region of a display unit and displaying information of an event,which is indicated by an icon located in a specific region of the eventdisplay region, in an information display region of the display unit;and an event-of-interest changing step of, when a swipe operation in theevent display region is detected, scrolling icons displayed in the eventdisplay region according to the swipe operation to change the display ofthe information display region to information corresponding to the eventindicated by the icon located in the specific region.

According to a thirteenth aspect of the present invention, in thedisplay method of an optical time domain reflectometer according to thetwelfth aspect of the present invention, in the display step, aplurality of icons corresponding to the events may be displayed in orderof the events in the optical fiber under test.

According to a fourteenth aspect of the present invention, in thedisplay method of an optical time domain reflectometer according to thetwelfth aspect of the present invention, in the display step, the iconof the event located in the specific region may be displayed as an iconlarger than icons of events located outside the specific region.

According to a fifteenth aspect of the present invention, in the displaymethod of an optical time domain reflectometer according to thethirteenth aspect of the present invention, in the display step, theicon of the event located in the specific region may be displayed as anicon larger than icons of events located outside the specific region.

A display method of an optical time domain reflectometer according to asixteenth aspect of the present invention includes: a measurement stepof making a light pulse be incident on an optical fiber under test andreceiving return light that returns due to reflection or scattering ofthe light pulse in the optical fiber under test; an event detection stepof detecting events where an intensity of the return light changes usinga measurement result in the measurement step; a display step ofdisplaying a plurality of icons corresponding to the events in an eventdisplay region of a display unit and displaying information of an event,which is indicated by an icon located in a specific region of the eventdisplay region, in an information display region of the display unit;and an event-of-interest changing step of, when a tap operation on theicon in the event display region is detected, scrolling icons displayedin the event display region to move the icon, at which the tap operationhas been detected, to the specific region so that the display of theinformation display region is changed to information corresponding tothe event indicated by the icon located in the specific region.

According to a seventeenth aspect of the present invention, in thedisplay method of an optical time domain reflectometer according to thesixteenth aspect of the present invention, in the display step, aplurality of icons corresponding to the events may be displayed in orderof the events in the optical fiber under test.

According to an eighteenth aspect of the present invention, in thedisplay method of an optical time domain reflectometer according to thesixteenth aspect of the present invention, in the display step, the iconof the event located in the specific region may be displayed as an iconlarger than icons of events located outside the specific region.

According to a nineteenth aspect of the present invention, in thedisplay method of an optical time domain reflectometer according to theseventeenth aspect of the present invention, in the display step, theicon of the event located in the specific region may be displayed as anicon larger than icons of events located outside the specific region.

In addition, the inventions described above can be combined in any waypossible.

Advantage of the Invention

According to the present invention, it is possible to provide an opticaltime domain reflectometer in which an event of interest can be changedthrough an intuitive operation and failure points can be checkedefficiently even in a case where the number of events increases.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of the configuration of an optical time domainreflectometer according to an embodiment.

FIG. 2 shows an example of the screen configuration in a firstembodiment.

FIG. 3 shows an example of the screen configuration after changing anevent of interest in the first embodiment.

FIG. 4 shows an example of the screen configuration after tapping atouch key KR in the first embodiment.

FIG. 5 shows an example of the screen configuration after tapping atouch key KL in the first embodiment.

FIG. 6 shows a second display example of the event display region.

FIG. 7 shows a third display example of the event display region.

FIG. 8 shows a fourth display example of the event display region.

FIG. 9 shows an example of the screen configuration in a secondembodiment.

FIG. 10 shows an example of the screen configuration in a thirdembodiment.

FIG. 11 shows an example of the screen configuration in Non-patentDocument 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying diagrams. In addition, thepresent invention is not limited to the embodiments shown below. Theseembodiments are only illustrative, and the present invention can beimplemented in forms having been subjected to various modifications andimprovements based on the knowledge of those skilled in the art. Inaddition, it is assumed that components denoted by the same referencenumerals in this specification and diagrams are the same.

First Embodiment

FIG. 1 shows an example of the configuration of an optical time domainreflectometer according to the present embodiment. An optical timedomain reflectometer 91 according to the present embodiment includes anOTDR waveform measurement unit 11, a central processing unit (CPU) 12, adisplay unit 13, and an operation detection unit 14. The operationdetection unit 14 detects the operation of the operator. The displayunit 13 according to the present embodiment has the operation detectionunit 14 using a touch panel.

The OTDR waveform measurement unit 11 functions as a measurement unit,and measures the OTDR waveform of an optical fiber under test 92 bymaking a light pulse be incident on the optical fiber under test 92 andreceiving return light that returns due to reflection or scattering ofthe light pulse in the optical fiber under test 92. The CPU 12 functionsas an event detection unit, and detects an event by analyzing the OTDRwaveform. Here, the event is any failure point where the intensity ofreturn light changes. Any failure is, for example, connection,branching, bending, and fusion. The CPU 12 outputs the display data ofthe OTDR waveform analysis result to the display unit 13. Then, thedisplay unit 13 displays various kinds of information including the iconof the event of the optical fiber under test 92.

FIG. 2 shows an example of the screen configuration according to thepresent embodiment. In an event display region A_(IV), icons of three ormore events Iv18 to Iv24 that are continuous on the optical fiber undertest 92 are displayed. The respective icons are connected to each otherby a straight line indicating the optical line. A symbol according tothe type of failure is given to each icon. Accordingly, theclassification of failure and the chronological order of events in theoptical fiber under test 92 are displayed at the same time. The icon ofthe event Iv21 disposed in a specific region A_(ATT) of the eventdisplay regions A_(IV) is displayed in an enlarged manner as an event ofinterest.

A color or a pattern determined by the pass or fail of thecharacteristic of events may be given to each icon. For example, thebackground or the outer edge of an icon is displayed in blue or greenwhen the event is a pass, and the background or the outer edge of anicon is displayed in red when the event is a fail. Thus, by determiningthe color of each icon according to the pass or fail of the event, it ispossible to express that a failed event is present even in a case whereicons to be displayed in the event display region A_(IV) are made small.

The display unit 13 displays the information of the event of interest inthe information display region A_(INF). For example, in a case where theevent of interest is the event Iv21, the CPU 12 displays at least one ofa distance from the incidence end or the far end of the optical fiberunder test 92 to the event Iv21, a return loss in the event Iv21, a lossvalue in the event Iv21, a magnified waveform in the event Iv21 in theOTDR waveform, and pass or fail of the event Iv21 in the informationdisplay region A_(INF).

It is preferable that the display unit 13 displays the pass or fail inthe entire optical fiber under test 92 in the information display regionA_(INF). In addition, it is preferable that the display unit 13 displaysa loss value in the entire optical fiber under test 92 in theinformation display region A_(INF). By displaying both the loss value inthe entire optical fiber under test 92 and the loss value in the eventIv21, it is possible to grasp the degree of contribution of the lossvalue in the event Iv21.

The operation detection unit 14 detects the amount of swipe operation D1in the event display region A_(IV). Then, the CPU 12 functions as anevent-of-interest changing unit, and scrolls the icons of events to bedisplayed in the event display region A_(IV) according to the amount ofswipe operation D1. Accordingly, when the swipe operation D1 isperformed from left to right, the events Iv18 to Iv24 move horizontallyto the right. At this time, the event of an icon closest to the specificregion A_(ATT) during the movement always becomes an event of interest.Therefore, as shown in FIG. 3, icons of the events Iv15 to Iv21 afterthe movement are displayed in the event display region A_(IV). It isalso possible to give inertia to movement by sensing the acceleration ofthe swipe.

Here, icons of the events Iv20 and Iv19 pass through the specific regionA_(ATT) in order until the icon of the event Iv18 moves to the specificregion A_(ATT). At this time, the icons of the events Iv20 and Iv19 arealso displayed in an enlarged manner when passing through the specificregion A_(ATT). Thus, when the events pass through the specific regionA_(ATT) by the swipe operation D1, it is preferable to display the iconof an event, which is displayed in the specific region A_(ATT), in anenlarged manner.

In addition, when the icons of the events Iv20 and Iv19 pass through thespecific region A_(ATT) in order, the CPU 12 functions as anevent-of-interest changing unit, and changes information displayed inthe information display region A_(INF) for each of the events Iv20 andIv19 of the icons located in the specific region A_(ATT). Thus, by swipeoperation of tracing the screen left and right with a finger or thelike, it is possible to scroll the icon column. As a result, the eventof the specific region A_(ATT) always becomes an event of interest.

It is preferable that the operation detection unit detects a tapoperation on touch keys KR and KL displayed on the display unit 13. Whenthe touch key KR is tapped once, the CPU 12 moves the icon of the eventdisplayed in the event display region A_(IV) to the left. When the touchkey KR is tapped once in a display state shown in FIG. 2, icons ofevents Iv25 to Iv31 are displayed in the event display region A_(IV) andthe icon of the event Iv28 is disposed in the specific region A_(ATT),as shown in FIG. 4. When the touch key KL is tapped once, the CPU 12moves the icon of the event displayed in the event display region A_(IV)to the right. When the touch key KL is tapped once in the display stateshown in FIG. 2, icons of events Iv11 to Iv17 are displayed in the eventdisplay region A_(IV) and the icon of the event Iv14 is disposed in thespecific region A_(ATT), as shown in FIG. 5. In addition, it is needlessto say that the touch keys KR and KL may be set to perform movement ofone icon by one tap operation.

It is preferable that the operation detection unit 14 detects a pinchoperation and a stretch operation in the event display region A_(IV). Inthis case, the icon of a non-interest event is reduced according to thepinch operation, and the icon of a non-interest event is enlargedaccording to the stretch operation.

As described above, in the present embodiment, since it is possible tochange the event of interest by the swipe operation or the operation oftapping the touch keys KR and KL, the change of the event of interestthat requires multiple operations can be realized by one operation.Therefore, in the present embodiment, it is possible to provide theoptical time domain reflectometer 91 in which an event of interest canbe changed through an intuitive operation and failure points can bechecked efficiently even in a case where the number of events increases.

The specific region A_(ATT) can be any region of the event displayregion A_(IV). For example, the specific region A_(ATT) may be thecenter of the event display region A_(IV) shown in FIGS. 2 and 3, or maybe the end of the event display region A_(IV).

The number of icons of events displayed in the event display regionA_(IV) can be any number of 3 or more. For example, the number of iconsof events displayed in the event display region A_(IV) may be 8 or morewithout being limited to 7 shown in FIGS. 2 and 3.

In the swipe operation example shown in FIGS. 2 and 3, a swipe operationto the right is shown. However, also in the case of a swipe operation tothe left, the events Iv18 to Iv24 move horizontally to the left and theevent of an icon closest to the specific region A_(ATT) during themovement always becomes an event of interest, similar to the case of theswipe operation to the right.

In FIGS. 2 to 5, an example is shown in which the icons displayed in theevent display region A_(IV) are disposed in the horizontal direction ofthe screen. However, the present invention is not limited thereto. Forexample, as shown in FIG. 6, icons may also be disposed in the verticaldirection of the screen. In this case, since the optical lines areconnected vertically, it is preferable to rotate the symbol of each iconin a direction according to the straight line indicating the opticalline.

In addition, in FIGS. 2 to 5, an example is shown in which the iconsdisplayed in the event display region A_(IV) are disposed atpredetermined intervals. However, the present invention is not limitedthereto. For example, as shown in FIG. 7, non-interest events may bedisplayed so as to overlap each other outside the specific regionA_(ATT).

In this case, regions where icons overlap each other may be uniform, butit is preferable that the regions are not uniform. For example, in theoverlapping between icons, it is preferable that the icon of an eventfar from the event of interest is larger than the icon of an event closeto the event of interest. Therefore, since it is possible to display alarger number of icons of events in the event display region A_(IV), itis possible to grasp how many events of the optical fiber under test 92are present at a glance.

In addition, in FIGS. 2 to 5, an example is shown in which the iconsdisplayed in the event display region A_(IV) are linearly disposed.However, the present invention is not limited thereto. Non-interestevents may be disposed in a curved manner outside the specific regionA_(ATT). Any curve can be applied. For example, as shown in FIG. 8, anarc shape can be applied. Therefore, it is possible to display a largernumber of icons of events in the event display region A_(IV).

In this case, as shown in FIG. 8, it is preferable to displaynon-interest events so as to overlap each other outside the specificregion A_(ATT). In this case, regions where icons overlap each other maybe uniform, but it is preferable that the regions are not uniform. Forexample, in the overlapping between icons, it is preferable that theicon of an event far from the event of interest is larger than the iconof an event close to the event of interest.

In the screen configuration shown in FIG. 8, it is possible to display alarge number of events in the event display region A_(IV). Accordingly,icons of all events of the optical fiber under test 92 may be displayedin the event display region A_(IV). In this case, when the CPU 12functions as an event-of-interest changing unit, the CPU rotates icons,which are circularly arranged, while switching the event of interestaccording to the swipe operation D1.

Second Embodiment

FIG. 9 shows an example of the screen configuration according to thepresent embodiment. In the present embodiment, in addition to thefunction in the first embodiment, the operation detection unit 14further detects a tap operation on the icon displayed in the eventdisplay region A_(IV). Then, the CPU 12 functions as anevent-of-interest changing unit, and moves the icon, at which a tapoperation has been detected, to the specific region A_(ATT).

For example, when the icon of the event Iv18 that is a non-interestevent is pressed (tapped), the CPU 12 scrolls icons displayed in theevent display region A_(IV) to move the icon of the event Iv18 to thespecific region A_(ATT) so that the event Iv18 becomes an event ofinterest. Thus, by tapping an event that needs to be an event ofinterest, events in the event display region A_(IV) move horizontally ina moment. As a result, the tapped event becomes an event of interest.Therefore, as shown in FIG. 3, the icons of the events Iv15 to Iv21after the movement are displayed in the event display region A_(IV).

At this time, similar to the case of the swipe operation D1, it ispreferable to set the events Iv20 and Iv19 as events of interest whenthe icons of the events Iv20 and Iv19 pass through the specific regionA_(ATT).

Third Embodiment

The CPU 12 detects an event occurrence point when detecting an eventusing the OTDR waveform. The display unit 13 displays the occurrencepoint of each event in the entire optical fiber under test 92 in anoccurrence point display region A_(P).

FIG. 10 shows an example of the screen configuration according to thepresent embodiment. In the present embodiment, as an example, a case isshown in which occurrence points P18 to P24 of events Iv18 to Iv24 aredisplayed in the occurrence point display region A_(P). For example, theoccurrence point display region A_(P) includes a straight line showingthe entire optical fiber under test 92, and the occurrence points P18 toP24 of events for the entire optical fiber under test 92 on the straightline are displayed.

Here, it is preferable that a color or a pattern determined by the passor fail of the characteristic of events may be given to each of theoccurrence points P18 to P24. Therefore, it is possible to quicklyidentify the occurrence point of an event for which the characteristicof events is a fail.

In the present embodiment, in addition to the function in the firstembodiment, the operation detection unit 14 further detects a tapoperation on the occurrence points P18 to P24 displayed on the displayunit 13. For example, it is assumed that the occurrence point P18 hasbeen tapped. In this case, the CPU 12 functions as an event-of-interestchanging unit, and scrolls the icons displayed in the event displayregion A_(IV) to move the icon of the event Iv18 of the occurrence pointP18, at which a tap operation has been detected, to the specific regionA_(ATT). Therefore, as shown in FIG. 3, the icons of the events Iv15 toIv21 after the movement are displayed in the event display regionA_(IV).

Thus, in the present embodiment, by tapping an event occurrence point ofinterest, events in the event display region A_(IV) move horizontally ina moment. As a result, the tapped event becomes an event of interest. Atthis time, similar to the case of the swipe operation D1, it ispreferable to set the events Iv20 and Iv19 as events of interest whenthe icons of the events Iv20 and Iv19 pass through the specific regionA_(ATT).

Fourth Embodiment

Although the event of interest is only one point in the first to thirdembodiments, the event of interest is two points in the presentembodiment. The optical time domain reflectometer 91 according to thepresent embodiment changes the display of the display unit 13 accordingto the tap operation in the event display region A_(IV).

As the optical time domain reflectometer 91 according to the presentembodiment, it is possible to use the configuration shown in FIG. 1. Inthe case of applying the present embodiment to the optical time domainreflectometer 91 according to the first and second embodiments, it ispossible to use the screen configurations shown in FIGS. 2 to 9. In thecase of applying the present embodiment to the optical time domainreflectometer 91 according to the third embodiment, it is possible touse the screen configuration shown in FIG. 10.

The operation detection unit 14 detects a tap operation on the icons oftwo different events. For example, a tap operation is performed on theicons of the events Iv18 and Iv20. Then, the display unit 13 highlightsthe icons of the events Iv18 and In20 where the tap operation has beendetected. As examples of the highlighting, the icons may be enlarged, ormay be made to have a different color from the other icons.

The CPU 12 functions as a calculation unit, and calculates the loss andthe distance of the events Iv18 and In20 of the icons where the tapoperation has been detected. The display unit 13 displays the loss andthe distance calculated by the CPU 12 in the information display regionA_(INF).

As described above, in the present embodiment, it is possible to furtherperform display in a case where the event of interest is two points inaddition to the first to third embodiments in which the event ofinterest is one point.

However, when applying the present embodiment to the second embodiment,the operation detection unit 14 is made to be able to identify whetherthe event of interest is one point or two points. For example, in a casewhere only one icon is tapped, the operation detection unit 14determines that the event of interest is one point. In addition, in acase where two icons are tapped at the same time, the operationdetection unit 14 determines that the event of interest is two points.

Fifth Embodiment

In the optical time domain reflectometer 91 according to the presentembodiment, the event of interest is two points as in the fourthembodiment. The optical time domain reflectometer 91 according to thepresent embodiment changes the display of the display unit 13 accordingto the tap operation in the occurrence point display region A_(P).

As the optical time domain reflectometer 91 according to the presentembodiment, it is possible to use the configuration shown in FIG. 1. Inthe case of applying the present embodiment to the optical time domainreflectometer 91 according to the first to fourth embodiments, it ispossible to use the screen configuration shown in FIG. 10.

In the present embodiment, the operation detection unit 14 detects a tapoperation on two different occurrence points in the occurrence pointdisplay region A_(P). For example, a tap operation is performed on theoccurrence points P18 and P20. Then, the display unit 13 highlights theoccurrence points P18 and P20 where the tap operation has been detected.As examples of the highlighting, a mark indicating an occurrence point,such as P18 shown in FIG. 10, may be enlarged, or the color of the markindicating an occurrence point may be changed.

The CPU 12 functions as a calculation unit, and calculates the loss andthe distance between the occurrence points P18 and P20 where a tapoperation has been detected. The display unit 13 displays the distanceand the loss calculated by the CPU 12 in the information display regionA_(INF).

As described above, in the present embodiment, it is possible to furtherperform display in a case where the event of interest is two points inaddition to the first to third embodiments in which the event ofinterest is one point. However, when applying the present embodiment tothe third embodiment, the operation detection unit 14 is made to be ableto identify whether the event of interest is one point or two points.

For example, in a case where only one occurrence point is tapped, theoperation detection unit 14 determines that the event of interest is onepoint. In addition, in a case where two occurrence points are tapped atthe same time, the operation detection unit 14 determines that the eventof interest is two points.

The present invention can be applied to the information andcommunication industry.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

-   -   11: OTDR waveform measurement unit    -   12: CPU    -   13, 113: display unit    -   14: operation detection unit    -   91: optical time domain reflectometer    -   92: optical fiber under test

What is claimed is:
 1. An optical time domain reflectometer, comprising: a measurement unit that makes a light pulse be incident on an optical fiber under test and receives return light that returns due to reflection or scattering of the light pulse in the optical fiber under test; an event detection unit that detects events where an intensity of the return light changes; a display unit that displays a plurality of icons corresponding to the events in an event display region and that displays information of an event, which is indicated by an icon located in a specific region of the event display region, in an information display region; an operation detection unit that detects an amount of swipe operation in the event display region; and an event-of-interest changing unit that scrolls icons displayed in the event display region according to the amount of swipe operation, which has been detected by the operation detection unit, and changes the display of the information display region to information corresponding to the event indicated by the icon located in the specific region.
 2. The optical time domain reflectometer according to claim 1, wherein the operation detection unit detects a tap operation on the icon, and the event-of-interest changing unit scrolls icons displayed in the event display region to move the icon, at which the tap operation has been detected, to the specific region.
 3. The optical time domain reflectometer according to claim 1, wherein the display unit displays an occurrence point of each event in the entire optical fiber under test in an occurrence point display region, the operation detection unit detects a tap operation on the occurrence point in the occurrence point display region, and the event-of-interest changing unit scrolls icons displayed in the event display region to move the icon of the event of the occurrence point, at which the tap operation has been detected, to the specific region.
 4. The optical time domain reflectometer according to claim 2, wherein the display unit displays an occurrence point of each event in the entire optical fiber under test in an occurrence point display region, the operation detection unit detects a tap operation on the occurrence point in the occurrence point display region, and the event-of-interest changing unit scrolls icons displayed in the event display region to move the icon of the event of the occurrence point, at which the tap operation has been detected, to the specific region.
 5. The optical time domain reflectometer according to claim 1, wherein the operation detection unit detects a tap operation on two icons indicating two different events, a calculation unit that calculates a loss and a distance between the two events where the tap operation has been detected is further provided, and the display unit highlights the icon where the tap operation has been detected and displays the distance and the loss calculated by the calculation unit in the information display region.
 6. The optical time domain reflectometer according to claim 1, wherein the display unit displays an occurrence point of each event in the entire optical fiber under test in an occurrence point display region, the operation detection unit detects a tap operation on two different occurrence points in the occurrence point display region, a calculation unit that calculates a loss and a distance between the two occurrence points where the tap operation has been detected is further provided, and the display unit highlights the occurrence points where the tap operation has been detected and displays the distance and the loss calculated by the calculation unit in the information display region.
 7. The optical time domain reflectometer according to claim 1, wherein the display unit displays a plurality of icons corresponding to the events in order of the events in the optical fiber under test.
 8. The optical time domain reflectometer according to claim 2, wherein the display unit displays a plurality of icons corresponding to the events in order of the events in the optical fiber under test.
 9. The optical time domain reflectometer according to claim 5, wherein the display unit displays a plurality of icons corresponding to the events in order of the events in the optical fiber under test.
 10. The optical time domain reflectometer according to claim 1, wherein the display unit displays the icon of the event located in the specific region as an icon larger than icons of events located outside the specific region.
 11. The optical time domain reflectometer according to claim 2, wherein the display unit displays the icon of the event located in the specific region as an icon larger than icons of events located outside the specific region.
 12. A display method of an optical time domain reflectometer, comprising: a measurement step of making a light pulse be incident on an optical fiber under test and receiving return light that returns due to reflection or scattering of the light pulse in the optical fiber under test; an event detection step of detecting events where an intensity of the return light changes using a measurement result in the measurement step; a display step of displaying a plurality of icons corresponding to the events in an event display region of a display unit and displaying information of an event, which is indicated by an icon located in a specific region of the event display region, in an information display region of the display unit; and an event-of-interest changing step of, when a swipe operation in the event display region is detected, scrolling icons displayed in the event display region according to the swipe operation and changing the display of the information display region to information corresponding to the event indicated by the icon located in the specific region.
 13. The display method of an optical time domain reflectometer according to claim 12, wherein, in the display step, a plurality of icons corresponding to the events are displayed in order of the events in the optical fiber under test.
 14. The display method of an optical time domain reflectometer according to claim 12, wherein, in the display step, the icon of the event located in the specific region is displayed as an icon larger than icons of events located outside the specific region.
 15. The display method of an optical time domain reflectometer according to claim 13, wherein, in the display step, the icon of the event located in the specific region is displayed as an icon larger than icons of events located outside the specific region.
 16. A display method of an optical time domain reflectometer, comprising: a measurement step of making a light pulse be incident on an optical fiber under test and receiving return light that returns due to reflection or scattering of the light pulse in the optical fiber under test; an event detection step of detecting events where an intensity of the return light changes using a measurement result in the measurement step; a display step of displaying a plurality of icons corresponding to the events in an event display region of a display unit and displaying information of an event, which is indicated by an icon located in a specific region of the event display region, in an information display region of the display unit; and an event-of-interest changing step of, when a tap operation on the icon in the event display region is detected, scrolling icons displayed in the event display region to move the icon, at which the tap operation has been detected, to the specific region so that the display of the information display region is changed to information corresponding to the event indicated by the icon located in the specific region.
 17. The display method of an optical time domain reflectometer according to claim 16, wherein, in the display step, a plurality of icons corresponding to the events are displayed in order of the events in the optical fiber under test.
 18. The display method of an optical time domain reflectometer according to claim 16, wherein, in the display step, the icon of the event located in the specific region is displayed as an icon larger than icons of events located outside the specific region.
 19. The display method of an optical time domain reflectometer according to claim 17, wherein, in the display step, the icon of the event located in the specific region is displayed as an icon larger than icons of events located outside the specific region. 